This invention relates to disposable absorbent pads such as diapers, sanitary napkins, underpads, surgical dressings and wipes, and the like.
Non-woven, bonded, textile/pulp fabrics, hydraulically-entangled and mechanically-bonded textile fiber fabrics, and relatively thin, spun-bonded fabrics are the usual facing fabrics for disposable sanitary and convenience products. Such fabrics should be relatively soft and conformable, capable of extended contact with external and internal body surfaces without causing chafing or allergenic reactions, and also capable of transmitting body fluids to a central absorbent core or layer while maintaining skin dryness. However, such facing fabrics are relatively expensive inasmuch as synthetic polymeric materials must be first converted to textile filaments or fibers, and the synthetic or natural textile length fibers must be further converted into a web structure and mechanically, hydraulically, or adhesively bonded to produce a facing fabric which meets the aforementioned requirements.
In order to minimize the cost of disposable sanitary and convenience products it is desirable to develop disposable absorbent pads which do not utilize a fabric-type facing sheet yet which retain the above comfort and conformability characteristics.
U.S. Pat. No. 3,431,911 to Meisel discloses an absorbent pad having a facing layer made of reticulated polymeric foam, such as polyurethane foam, which is disposed over an underlying layer of fluid absorbent material. However, foamed facing layers have a coarse structure, are relatively bulky, and tend to increase the overall dimensions of the absorbent pad. Moreover, the open-cell structure of the foam layer may cause undesirable reverse pumping action when an absorbent pad of such type is compressed while being used. In addition, foam surfaces do not have the desired surface aesthetics.
U.S. Pat. No. 3,901,240 to Hoey discloses a liner of crushed, thermosettable polymeric latex foam for an absorbent pad, which liner disintegrates when the absorbent pad is flushed away. However, the liner has relatively low cohesive strength and is relatively dense and bulky.
In our copending application, U.S. Ser. No. 591,747, filed on June 30, 1975, now U.S. Pat. No. 3,967,623, are disclosed absorbent pads having a facing which is a perforate, substantially hydrophobic web of a thermoplastic polymeric material provided with an integral fibrous outer surface. We have now found that the bulkiness of an absorbent pad can be reduced and conformability of the pad to the user enhanced by providing a body fluid-permeable facing which is a relatively thin non-woven fibrous web made up of interconnected, molecularly oriented fiber elements having a fine denier.